Rack-cleaning device



l. W. JONES. RACK CLEANING DEVICE; APPLICATION FILED DEC.9, 1920.

Patented Oct. 4, 1921. 9 SHEETS-SHEET I.

1 I" 1/ I l 11111 151117 w. JONES. RACK CLEANING DEVICE. APPLICATION FILED DEC.9| 1920.

Patented Oct.- 4, 1921.

9 SHEETS-SHEET 2.

I. W. JONES.

RACK CLEANING DEVICE.

APPLICATION FILED 1150.9, 1920.

Patentd 001;. 4, 1921.

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RACK CLEANING DEVICE.

APPLICATION FILED 050.9. 1920.

1,39%647. Patented 0017. 4, 1921.

9 SHEETS-SHEET 4- R1 AL IIIH I I II I l II I I I "EL L9 w \N 1 i lg v I '0 I 1 I N 5 1H6 m I" I! I 1M? 5' 'i 1' H 'E-'I-I"I'.

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/?2/z/e?u0r fldorney l. JONES.

RACK CLEANING DEVICE. APPLICATION FILED nEc.s. 19 20.

Patented Oct. 4, 1921.

9 SHEETSSHEET 5.

I. W. JONES.

RACK CLEANING DEVICE- APPLICATION FILED 020.9. 1920.

Patented Oct. 4, 1921.

9 SHEETS-SHEET 6.

I. JONES.

RACK cmwme DEVICE.

APPLICATION FILED DEC-9, 1920. v

Patented Oct. 4, 1921.

9 SHEETS-SHEET 7- I. w. JONES.

RACK CLEANING DEVICE.

APPLICATION FILED DEC.9, 1920. 1,392,647, r Patented Oct. 4, 1921.

9 SHEETS-SHEET 8.

mm my QL=J I. W. JONES.

RACK CLEANING DEVICE.

APPLICATION man 050.9. 1920.

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, 1 1 darney IRA W. JONES, OFIEBANON, MAINE.

RACK-CLEANING DEVICE.

aeaca'r.

To all ham it may concern Be it known that I, Ina Jonas, a citi- Zen ofthe United States, residing at Lebpractical mechanism anon, in the county of York and State of LMaine. have invented certain Improvements in a Rack-Cleaning Device, of which the following description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings indicating like parts in the several figures.

This invention relates to devices and apparatus for cleaning the racksor gratings that are placed across the intake end of a mill race and in similar'locations to catch debris which otherwise would be carried to the turbines or other water driven apparatus by the inrushing current of water.

It is necessary at frequent intervals to clean off the sticks, leaves and other debris that lodges on the .gratings, and it has been customary heretofore to perform this cleaning operation with the aid of a long handled rake. In many installations this work can be performed satisfactorily in this manner, but on the larger dams where the gratings are deep it is very difficult to perform this cleaning operation by hand. This is especially true at certain seasons of the year, particularly in the autumn, when leaves carried by the current of water collect in great quantities on the gratings,t hese accumulations occasionally being sufficient to cause a serious reduction in the flow of water to the turbines and thus interfere very materially with the service supplied by the turbines. Moreover, the difiioulty of keeping the gratings clear with the apparatus now commonly used has been increased by the tendency in newer and larger installations to increase the depthof the gratings.

,With a view to overcoming this ditficulty it has been proposed heretofore to perform this cleaning operation by some power driven apparatus and various forms of apparatus of this character have been devised. None of these forms, however, so far as- I have been able to learn, have proved satisfactory, and it is the chief object of the present invention to devise a thoroughly for cleaning these gratings.

' Themanner in which it is proposed to'accomplish this object will be readily understood from the following description when Specification of Iietters Patent;

the plane indicated by the line 33, Fig.

Patented Oct. 4, 1921.

Application filed December 9, 1920. Serial No. 429,429.

read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claims.

Referring now to the drawings,

Figure 1 isa view partly in vertical cross section and partly in side elevation illustrating a rack cleaning mechanism constructed in accordance with the'present invention; V p

Fig.2 is a front elevation of the mechanism shown in Fig. 1; i

Fig. 3 is a cross sectional plan view on Fig. l is a front elevation of the rake; 5 is a vertical cross sectional View the rake;

Fig. 6 is aside elevation, partly in cross section, illustrating a portion of the mechanism that automatically stops the dumping operation f V Figs. 7 and 8 are side'and plan views, re-

spectively, of an additional part of the -mechanism that performs the dumping op- 'eration;

Fig. 9 is a vertical cross sectional view of a part of the mechanlsm that raises and I lowers the rake;

ing mounted on a track 3 which runs along the top of the dam 4. The rake 5, in the position shown in Figs. 1 and 2, rests on an apron or runway 6 which is carried by the car and extends down close to the upper end of the rack or grating 7 that covers the in take end of the mill race. 'The'rake 5 is mounted to reciprocate up and down over the grating 7, being guided partly on'the grating and partly on the apron 6, and dur-' ing its upward or raking movement it gathers debris from the grating, carryingit upwardly over the apron 6 and dumping it into the upper end of a canal 8-wl1ich1lies between the track 3 and the rip-stream side ranged to have both raking and dumping.

movements and the car carries a. motorand suitable controlling mechanism for producing both of these movements of the rake. A controlling mechanism also is provided to enable the motor to drive the car when it is desired to transfer the rake from one part of the grating to another.

Proceeding now to the detailed descrip tion of the various parts of the apparatus,

the rake 5 consists of a series of teeth preferably made of bars of angular cross sec tion,;as clearly shown in Fig. 4, these bars being riveted to other angular members and 11, respectively, Fig. The ends of the teeth are cut off at an angle, as shown in Fig. 5, to form points which pro ect between t the bars of the grating,and the downwardly projecting flange of the angular member 10 limits the entrance of the points of the teeth between the bars, this flange riding'on the surface of the rating. The rake 5 is pivotally supportec on a shaft 12 by strips or clips 13 which partially encircle the shaft and are rivetedto certain of the teeth and to the downwardly projecting flange of the an lgle member 11. This construction is clearly "illustrated 1n l igs. 1 and 5. A pair of cables 1 1 are connected to the forward portion of the rakeand another pair of cables 15 connected to the rearward edge of the rake cooperate with the cables 14 to control the angular position of the rake. The teeth 'at the opposite ends of the rake are extended, as shown in Fig. 5, considerably beyond the right-hand side of the shaft and the cables15 are connected to these extended members.

The shaft 12forms part of a frame which includes an ,upper shaft 16, side pieces l7-17 preferably of channel cross section, and a plate 18 which connects the side membe1s17-17 vand is reinforced at both its upper and lower edges by angle members 19-19. This plate formsa back for the rake and prevents the debris from sliding 'backwardly off the teeth. The frame forms the supportfor the rake 5 and is itself supported or mounted on two pairs of rolls or trucks designated a't'20 and 21, respectively,

the rolls 20 rotating on the ends of the upper shaft 16 while the rolls 21 rotate on the lower shaft 12. These lower rolls are much larger in diameter than the upper rolls and they are each provided with a peripheral rib 22 which enters between the ribs of the grating 7 and prevents the rake from slipping sidewise on th grating. The cables 14 run over grooved pulleysfor sheaves 23 which are rotatablyfmounted on the shaft 16, while the other pair of cables 15 run over similar sheaves 24 rotating on stub shafts which aresupported in channel bars 25- 25 secured to the upper part of the frame.

It will now be evident that'if thetwo Each of the cables 15, howeveig is also led from one of the pulleys 27 over a pulley 29 which is mounted on a movable axis, and the cable is led from this pulley over another one of the pulleys 27 and thence'to the drum 28. The drums 28'28are keyed to a hollow shaft 30 to which also is fixed a worm wheel 31' which meshes with a worin'fast on the shaft 32. This shaft carries two loose pulleys 33 and34, respectively, and the fast pulley 35 positioned between theloose pulleys. Open and crossedbelts driven from pulleys on the main driving shaft 36normally run 011 the respective pulleys 33 and 3st, and these belts are controlled by pivoted belt shippers 37 and 38. The construction of this controlling mechanism is best llustrated in' Figs. 12and 13. Referring to these figures it will be seen that the belt shipper 37 has pivoted thereto a link 39 which carries a roll running in cam slot 10 formed in a plate 41 which is mounted to slide horizontally in the 'upper. part of the bearing bracket 42. The other belt shipper 38 is siinilarly con nected to a linlrtt carrying a roll which runs in another cam path 45 in the plate d1.

A handlever 16 is fulcrumed on the bracket 12 and is connected by a link 47 to one end of the sliding plate i1. j Consequently, when the operatorwishes to rotate the drums 28-28 it is merely necessary for him to throw the hand lever 46 in one direction or the other to transfer either the crossed or open belt, as he desires, on to the fast pulley it being understood, of course, that if the open belt. is thrownon to the fast pulley it willrotate the drums in one direction, while if the crossed belt is transferred onto the fast pulleyit will rotate the drums in the opposite direction. 7 i 1 For the purpose of "holding the'drums stationarywvlienpower not applied to them, and also for the purpose of stopping the rotation of the drums quickly when either of'the driving belts are shifted'from a'fast to a loose pulley, a-brake mechanism is provided to operate. on the fast pulley 35. This mechanism comprises a brake shoe 4:8, Fig. 13, having a stud 't9 projecting upwardly therefrom, this'stud being connected through a loose joint to the lower end ofa bolt 50 which is threaded through the brake lever 51f V A spring 52 which is coiled about an upright rod 53 supported in 'astationary part of the frame bears on thelever 51 and normally holds the brake shoe -48 firmly against the surface ofthe fast pulley 35.

In other words, this spring normally applies the brake.

For the purpose of moving the brake 'levery51 in opposition to the spring 52, it

is fulcrumed on the rounding end of a stud 55 and is connected by a link 56 to one end This plate 41 is provided with between which the roll 59 rests when the plate 41 is in its'neutlal' position, as shown inFig. 12. When, however, the lever 46 is moved in either direction to shift one of the belts to the fast pulley,this movementof the belt 41 carries one of the cam lugs 60 or 61 under the roll 59 thus lifting this roll.

and-this motion is transmitted through the connections with the brake shoe to raise the brake shoe off the surface of the pulley 35..

It will now-be understood that the rake is normally stationary and that it is merely necessary for the operator to move the hand lever 46 in one direction or the other for the purpose of elther raising or lowering the rake. Inorder to relieve the operator from the necessity of stopping the movement of the rake when it has been either raised or lowered to the desired point, an automatic. stopping mechanism is provided.

Thismechanism comprises a shaft 63, Figs.

10 and 11', driven by a'sprocketand chain connection 64 .wlth the drum shart 80. =The sprocket wheel 65 is splined to the shaft 63 and is also threaded thereon, but is prevented from-*inoving longitudinally of the shaft by a dog 66. This shaft is threaded for a substantial dlstance from one end and consequently when the sprocket wheel 65' is rotated it not only rotates the shaft 63 but also moves'this shaft endwise through 7 its hearings.

-Near the opposite end of this shaft two dogs 67 and 68, respectively, are adjustably securedby set screws, and they :are mounted at opposite sides of a bar 69 which is mounted to shde atright angles to the shaft 63; This barcarries two lugs 70 and 71, respectively, positioned for engagement with the respective dogs 68 and 67 when either of these dogs have been transferred by the endwise movement of the 1 lever 72 and a link 73 to the sliding plate 41, thus moving the belt 41 back into its neutral position and shiftingthe belt that is on the fast pulley onto one of the loose pulleys.

In other words, when the operator has once shifted the lever 46 into the proper position to;:move the rake in the desired direction, the machine will automatically stop the movement of the rake at a substantially predetermined point. This point may be varied by adjusting the dogs 67 and 68 on the shaft. 63. j

The cables 14 and 15 are soadjusted that they hold the rake at substantially right angles to the grating during the upward or raking stroke of the rake. During this movement they clean the debris out of the grating, this debris being carried on the rake upwardlyover the apron 6. When the rake arrives'at substantially the upper limit of its movement it is then moved into an inclined-or tipped position for the purpose of dumping the debris into the canal 8. This movement is produced by pulling on the cables 15 so as to tip the rake in a counter-clockwise direction about the shaft 12.

It is for this purpose that the cables 15 are run over the pulleys 29. These pulleys are supported on a shaft mounted in trunnions (one of whic'h'is shown at 75, Fig. 1) that project upwardly from an I beam 76. The opposite ends of this beam are connected to the upper ends of connecting rods 77 and 78, respectively, the lower ends of these rods being connected, respectively, to a crank 79 and a crank pin 80 (see Figs. 2 and 9). The crank 79 is keyed to one end of a shaft 81 that lies within the hollow drum shaft 30, while the crank pin 80 is secured in a worm wheel 82 that is keyed'to the opposite end of this shaft. This worm wheel is driven by a worm fast on the shaft 83, Figs. 10

and 11,, having a fast pulley 84 and a. loose pulley 85 mounted thereon. The loose pulley 1s belted to the main driving shaft 36 and vthe belt is controlled by a shipper 86,

Figs. 3 and 8, which is operated from a hand lever 87 in exactly the same way that the belt shipper 38 is operated from the lever 46. That is. the lever 87 operates a sliding plate 88 like the plate 41 except that ithas only one cam slot therein, this plate having connections with the shipper 86 and with a. brake which operates on the fast pulley 84 similar to the corresponding con nections and brake mechanism above described in connection with the controlling mechanism and that previously described are simply those necessitated by the fact that this mechanism requires a fast and loose pulley, whereas the mechanism previously described included a fast pulley and two loose pulleys.

This mechanism is so timedwith reference to the hoisting and lowering mechanism which operates the rake, that the pulleys 29 are held at the upper limit of their movementwhile the rake isbeing raised. At the end of this raking stroke, however, the operator moves the dumping lever 87 forward thus transferring the belt on to the fast pulley 84 and thereby causing the shaft 81 torr'otate.

This motion carries the crank? 9 from the position in which it is shown-in Fig. 1 through an angle of 180, the pin 80 being similarly rotated and thus moves the pulleys 29 downwardly nd thereby shortens -(so 'to'speak) the'cables with reference movement of the at this time,

Mechanism is provided which automatr.

to the cables 14:. Thislproduces the dumprake' which is desired cally stops this tipping movement of the rake at substantially'a predetermined point.

It is evident that a half rotation of the crank 79 and pin80 produces the dumping movement of the rake and that another half rotation would straighten the rake or re store it to its original position. The automatic mechanism just mentioned, therefore, is arranged to stop the tipping movement of the rake either in its dumping or straightened position.

This mechanism is best illustrated in Figs. 6, '7 and 8 and it comprises two rolls 90 and 91 mounted at diametrically opposite the bell crank lever 96 fulcrumed at 97 and having another arm 98 which is. pivoted to a vertical rod '99. A curved bracket 100, Fig.7, is secured to the upper end of this rod andcarries a pin 101'which is adapted to enter a hole 102 in the sliding plate88 when this plate is pushed forward into position to throw the belt on to the fast pulley 84. A'spring 103,- Fig. 7, is connected to the lower end of the handle lever 87 so that it is tensioned when the lever is thrown forward to start the dumping mechanism, and this spring has sufficient strength to return the hand lever to its initial position again. When, however, the hand leverhas been moved forward, the pin 101 drops into the hole 102 and retains the plate 88 in its operative or running position until the pin is raised through the chain of connections just described and which are set into operation by the contact of o'ne of the rolls 90 or 91 with the arm 92. WVhen thi occurs the spring 103 immediately returns the plate 88' to the position shown in Fig. 8 thus shiftingz'the belt on to the loose pulley and applying the braketo the fast pulley 84.

.-Assinning now that the rake is at the lower limit of its movement, the operator I moves the hoisting lever 46 into the proper direction to causethe power driven mechanismabove described to raise-the rake thus *carrying thev load of debris up to the upper 'matically stops it in this position. erator next 'moves the hoisting member 46 into the reverse position thereby causing the.

men t.

edge of the apron 6. This upward stroke or movement of the rake is automatically 7 'driven mechanism above described tips the rake into its dumping. position and auto- The oplioisting mechanism to lower the rake and this movement of the rake is automatically erator next moves the dumping lever 8'7 forward again thus causing the straightening of the rake into position for the next raking movement, the tipping movement of the rake of course being stopped automate cally, as above described, when it has reached itsstraiglitened or raking position. f

guides or tracks 105, Fig.1, for the wheels 21 and on to which the wheels roll when the rake nears the upper limit of its move- These raised portions lift the rake into such a position that when the rake is tipped into its dumping position and is lowered again there is no danger of the teeth or the depending flange of-the part 20 catching on the upper edge of the apron.

For the purpose of moving the car 2 along the track, the car axle 106, Fig. 1, has a sprocket wheel 10? secured thereto which is connected by a sprocket chain with another sprocket wheel 108, Fig. ,3,'n'iounted fast on a shaft 109 which is supported in suitable bearings. This shaft is connected by a sprocket and chain drive 110 to another shaft 111 having a fast pulley 112 andtwo loose pulleys 113 and 114, respectively, mounted thereon. This shaft 111gis controlled and operated by a starting and stopping mechanism exactly like that which operates the shaft 32, this mechanism being controlled by an operating lever or handle 115, and being driven through open and crossed belts from the main driving shaft 36. Inasmuch as this starting andstopping mechanism is V exactly like that shown in 'Figs. '12 and 13, any detailed description of it here is unnecessary. It ;will be understood that it is merely necessary for the operative to push the lever 115 forward in order to move the 7 supplied to the motor 117 either through a trolley connection,'a storage battery, flexible cable, or in any other convenient manner. i Y

The apron 6 preferably is connected to the car through a hinge 120, Fig. 1, or through some other flexible joint which will allow the apron to have a certain amount of movement relatively to the carto accom modate itself to variations in the incline, of the rip-stream face of the dam, or to varia tions in the distance between the track and the tip-stream edge of the dam. It will be seen from an inspection of Fig. 2 that this apron is provided with upstanding edges 121at. its opposite sides to prevent the rake from slin 3111" sidewise off the aaron and L. :3

these edges are flared outwardly toward the lower part of the apron so that they will guide the rake into a central position on the apron as the rake is drawn upwardly in case such a guiding action should be necessary due to the rake having slipped sidewise on thegrating. As above stated, however, the peripheral ribs provided on the wheels 21--21'usually prevent any sidewise movement of the rake relatively to the grating. The apron also is provided with small trucks or rolls 122-122 which support it on the rip-stream face of the dam.

The car 2 preferably is equipped with a hoisting mechanism for the stop planks 124 which usually are employed in a dam. For this purpose each planlr section is provided with a ring bolt 125, Fig. 1, to be engaged by a hook 126 on the lower end of a cable 127 which is vwound on a drum 128, Fig. 3, fast on a shaft 129. This shaft is supported in suitable bearings mounted on a frame work which is secured to one side of the car, and it is driven through a clutch 130 of any convenient type. The clutch shown comprises a driven member fast on the shaft 129 and a driving member .on a shaft 131 mounted co-axially with the shaft-129, the drivingmember being splined to this shaft so that, it can bemoved into or out of engagement wit-h its cooperating clutch membenp Thev shaft 131 is driven through a worm gearing 132 from a cross shaft 133 having fast and loose pulleys 13-1 and 135, respectively, Fig. 1, which are belted to the driving shaft 36. The clutch is operated by a lever 137 which extends down wardly to a point within convenient reach of the operator. 7

The operation of this apparatus has been describedso completely in connection with the foregoing description of construction, that any further statement of operation is believed to be unnecessary. It will readily be appreciated however, that the invention provides an automatic rack cleaning apparatus of very sturdy and substantial construction which can be manufactured economically, can be conveniently controlled and operated, which is particularly suited to those installations in which great diiiiculty has been experienced in keeping the grating clear with the usual hand operated apparatus, and which generally meets the p 'actical requirements for power driven cleaning apparatus.

It will also be understood that while 1 have herein shown and described the best embodiment of the invention of which I am at present aware, that this disclosure has been made by way of illustration rather than by way of limitation, and that the invention may be embodied in many forms differing in details of construction from that shown without departing from the spirit or scope oftliis invention.

hat is claimed as new is:

1. The combination with a dam having a mill race therethrough and a grating across said race,of a car mounted for movement along said dam above said grating, a canal in the upper part of said dam, and a power operated ralre mounted on said car and open ative to rake debris out of said grating and deliver it to said canal.

.2. The combination with a dam having a mill race therethrough and a grating across said race, of a car mounted for movement along said dam above said gratingan apron carried by said car and movable therewith along the up-stream face of the dam, connections between said apron and car permitting a relative movement between these two members, and a rake mounted on said car and operative to clean the debris out of said grating and carry it upwardly over said apron.

3. The combination with a dam having a mill race therethrough and a'grating across said race. of a car mounted for movement along said dam above said grating, an apron carried by said car and movable therewith along the upstream face of the dam. said apron having a hinged connection with said car whereby a relative movement is per: mitted between the apron and car, and a power operated rake mounted on said car for cleaning debris out of said grating, and carrying it upwardly over said apron.

. 4c. The combination with a dam having a mill race therethrough and a grating across said race, of a car mounted formovement alongsaid dam above said grating, an apron Carried by said car and movable therewith along the up-stream face of: the dam, con nections between said apron and car permitting a relative movement between these two members, wheels supporting the lower part of said apron, and a powerloperated rake mounted to move up and down over said apron and operative to, clean debris out of said grating and carry it upwardly over the apron.

p 5. The'combination with a dam having a mill race therethrough and a grating across said race, of a car mounted for movement along said dam above said grating, an apron carried by said car and movable therewith along the upstream face of the dam, and a power Operated rakemounted to move up and down over said apron and grating'to clean the'debris out of said grating and carry it upwardly over the apron, the lower part of said apron being flared and having sides to guide said rake.

6. The combination with a 'dam having a mill race therethrough and a grating across said race, of a track running along the top of the dam, a: canal in said dam between said track'and the up-stream side of the dam, a car mounted on said track, and a power operated rake mounted on said car and operative to rake debris out of said grating and deliver it to said canal.-

' 7. The combination with a dam having a mill race therethrough and a grating across said race, of a motor car movable along said dam above said grating, and a power operated rake mounted on said car.

'8.The combination with a dam having a mill race therethrough and a grating across said race, of a car movable along said dam abov'esaid grating, a motor mounted on said car for operating the car, a power operated rake mounted on said car for cleaning debris out'of said grating, and means whereby said motor may be made to operate either the car or the rake. V

9. The combination with a dam having a mill race therethrough and a grating across said race, of a rake for cleaning the debris out of said grating, said rake having both raking and dumping movements, and power driven mechanism for producing said movements.

10. The combination with a dam having a mill race therethrough and a grating across said race, of a rake for cleaning the debris out of said grating, said rake having both raking anddumping movements, mechanism for giving said rake its raking movement,

' additional mechanism for producing said dumping movement, and independent controlling means for said mechanisms 11. The combination with a dam having a mill race therethrough and a grating across said race, of a rake for cleaning the debris out of said grating, said rake having both raking and dumping. movements, power driven mechanism for operating said rake, and means for automatically stopping the rake when it has completed a raking and dumpin movement.

' 12. The combination with a dam having a mill race therethrough and a grating across sa'id'rac'e, a rake for cleaning debris out of said grating, power driven mechanism for operating said rake, and means 'for automatically stopping the rake after ithas completed a predetermined operation.

13. The combination with a dam having a mill race therethrough and a grating across said race, a rake for clearing debris outof said grating, power driven mechanism for operating said rake, means for automatically stopping therake ata substantially predeterminedpoint in its cycle of movements.

la, The combination with a dam having a mill race therethrough and a grating across said race, a rake mounted to reciprocate up and down over said grating to'clean debris out of the grating, power driven'mecha nism for operating said rake, and means for automatically stopping said rake at substantially the upper-limit of its movement;

15. The combination with a dam having a mill race therethrough and a grating across said race, a'rake mounted to reciprocate up. and down over said grating to clean debris out of the grating, power driven mechanism for operating said rake, and means for automaticallystopping said rake when it has completed its cycle of operations. 7

16. The combination with a dam having a mill race therethrough and a grating across said race, a rake mounted to reciprocate up and downover said grating to clean debris out of the grating, power driven mechanism for operating said rake, and means for automatically stopping said rake at the lower limit of its movement.

-mil1 race therethrough and a grating across said race, of a rake mounted to reciprocate over said grating to clean debris out of the grating, said rake comprising a vseries of teeth, and a frame supporting said teeth for tipping movement relatively to the direction of said reciprocating motion. f

a 18. The combination with a dam having a mill race therethrough and a gratin across said race, of a rake mountedto reciprocate over said grating to clean .debrisout of the grating, said rake comprising a series of teeth, and aframe supporting said teeth for angular movement relatively to said frame.

19. The combination with 'a'dam having a mill ace therethrough and a grating across said race,"of a rake mounted to reciprocate over said grating to clean debris out of the grating, said rake comprising a series of teeth, and a frame supportlng said teeth. for

movement either into a raking position in which the teeth project into the spaces between the bars of said grating, or into an angular position away from said grating, and -means for moving saidrake upwardly while it is in its raking position and down-- *ardly again over said grating While it is in said angular position. i '7 V QOQ The combination with a dam having a mill. race therethrough and agrating-across said race, of a rake mounted to reciprocate over said grating to clean debris out of the grating, and wheels supporting said rake on said grating, said wheels and grating having inter-engaging members serving to prevent the rake from slipping sidewise on the grating.

21. The combination with a dam having a mill race therethrough and a grating across said race, of a rake mounted to reciprocate over said grating to clean debris out of the grating, and wheels supporting said rake on said grating, the peripheralsurfaces of said wheels being ribbed circumterentially to mesh with said grating and prevent the rake from slipping sidewise on the grating.

22. The combination with a dam having a mill race therethrough and a grating across said race, of a rake mounted to reciprocate up and down along said grating to clean the grating, mechanism for giving said rake its c]eaning movement, and means whereby the teeth of the rake are caused to travel downwardly over the grating at a substantially greater distance from the face of the grating than during the upward movement of the rake.

23. The combination with a dam having a mill race therethrough and a grating across said race, of a rake mounted to reciprocate up and down along said grating to clean the grating, mechanism for giving said rake its cleaning movement, said rake having teeth to enter the spaces between the bars of the grating, and means for limiting the extent of said entering movement.

24. The combination with a dam having a. mill race therethrough and a grating across said race, of a rake mounted to reciprocate up and down along said grating to clean the grating, mechanism for giving said rake its cleaning movement, said rake having teeth to enter the spaces between the bars of the grating, and a member located adjacent to the ends of said teeth to bear on the face of the grating and limit the movement of said teeth into said spaces.

25. The combination of a dam having a mill race therethrough and a grating across said race, of a car mounted for movement along said dam above said grating. a motor carried by said car, a rake mounted on said car and operative to clean debris out of said grating, power driven mechanism for *ing said rake bot-h raking and dinnping movements, and controlling mechanisms wherebw said motor may be made to operate the car and to produce said raking and dumping movements.

26. The combination of a dam having a mill race therethrough and a grating across said race, of a rake for cleaning debris out of said grating, said rake being mounted for tipping movement, cables supporting the rake at opposite sides of the axis about which it tips, means for winding said cables in unison to lift the rake, and means for producing a relative movement of said'cables to tip the rake. l

27. The combination of a dam having a millrace therethrough and a grating across said race, of a rake for cleaning debris out oi said grating, said rake being mounted for tipping movement, cables supporting the rake at opposite sides of the axis about which it tips, means for winding said cables in unison to lift the rake, means for producing a relative movement or said cables to tip the rake, and means for automatically stopping said relative movement when a substantially predetermined tipping action has beenproduced. 3 V W 28. The combination of a dam having a mill race therethrough and agrating across said race, of a rake mounted to reciprocate up and downover said grating, said rake being movable into either anormal raking position or a tipped dumping position, and operating mechanism for said rake for moving said rake upwardly over the grating in said normal position, for tipping the rake after it has reached substantially the upper limit of its movement to dump it, lowering the rake in its tipped position, and then straightening it in readiness for the next raking movement.

29. The combination of a dam having a mill race therethrough and a. grating across said race, of arake mounted to reciprocate up and down over said grating, cables sup porting said rake, drums on which said cables are wound to raise the rake and unwound to lower the rake, mechanism for driving said drums, and means for automatically stopping the drums substantially when the rake has reached either the upper or lower limit 01"? its movement.

30. The combination of a dam having a mill race therethrough and a grating across said race, of a rake mounted to reciprocate up and down over said grating, cables supporting said rake, drums on which said cables are wound to raisethe rake and unwound to lower the rake, mechanism for driving said drums, and means operated by said mechanism for automatically stopping the drums when a substantially predetermined movement of the rake has been completed.

31. The combinatioifof a dam having a mill race therethrough and a grating across said race. of a rake comprising a series of teeth, a shaft extending transversely of the teeth and on which the teeth are pivoted, wheels mounted for rotation on said shaft, and means for moving said rake up and down over said grating. I

32. The combination of a dam having a mill race therethrough and a grating across said race, a rake comprising a series of teeth, a frame supporting said teeth for tipping movement, wheels supporting said frame, and means for reciprocating said frame up and down over said grating.

33. The combination of a dam having a mill race therethrough and a grating across said race, of a rake for cleaning debris out of Said grating, said rake being mounted for tipping movement, two sets of cables supporting the rake at opposite sides of the axis about which it tips, power driven drums for Winding both sets of cables in unison to lift the rake, and means for acting on one set of cables between the drums and the raketo tip the rake. V

34:. The combination of a darn having a mill race therethrough and a grating aOI'OSS said race, of a rake for cleaning debris out oi'sald grating, said rake belng mounted for tlpplng movement, two sets oi cables supporting the rake at opposite sides of the axis 20 about which it tips, power driven drums for winding both sets of cables in unison to lift the rake, pulleys rotatable on stationary axes on which said cables are guided to said drum, additional pulleys mounted on mov-' 2 In testimony whereof I have signed my 30 name to this specification.

IRA W. JONES; 

